1. Field of the Disclosure
The present disclosure relates to phase locked loops and more specifically to an adaptive voltage to current converter in a voltage control oscillator of a phase locked loop.
2. Description of the Related Art
Phase locked loops (PLLs) are used in a variety of applications from telecommunications to electronic devices. For instance, PLLs are used for demodulating signals, generating periodic signals that have a frequency equal to an integer multiple of a reference periodic signal, in a clock distribution network of a large microprocessor, etc.
PLLs often include large capacitors for stabilizing the output signal and/or filtering high frequency noise that may be added to the input signals. As such, PLLs occupy a large area of an integrated circuit and increase the size of and cost of manufacturing the integrated circuits.
One way to reduce the size of the capacitor used for stabilizing the output signal and/or filtering high frequency noise is by reducing the gain of a voltage controlled oscillator (VCO) used for generating the output signal. Reducing the gain of the voltage controlled oscillator also reduces the frequency range of the PLL. As such, in high frequency applications, it would be beneficial to have a VCO with a large frequency range without using a large capacitor for stabilizing the output signal and/or filtering high frequency noise of the input signals.